Endocrine pt. 1

Thyroid Nodules

200

Describe the function of the two branches of the superior laryngeal nerve

• Superior laryngeal nerve:
  • Arises from the vagus nerve as it exits the skull base
  • Courses with the superior thyroid artery until 1 cm before the artery enters the superior pole capsule
  • External branch → motor function
    • It innervates the inferior constrictor and cricothyroid muscles.
    • This nerve is the most commonly injured nerve in thyroidectomies.
    • Injury leads to loss of voice projection and increased fatiguability of the voice.
  • Internal branch → sensory to larynx
    • Injury can increase the risk of aspiration.

400

Describe 3 sonographic findings (of thyroid nodules) that are concerning for underlying malignancy

Solid hypochoic nodule or solid hypoechoic

component of a partially cystic nodule with one

or more of the following features: 

1. irregular margins (infiltrative, microlobulated)

2.microcalcifications

3. taller than wide shape

4. rim calcifications with small extrusive soft tissue

component

5. evidence of extrathyroidal extension

600

The recurrent laryngeal nerve is (motor, sensory, or both)

injury to the RLN results in this?

• Responsible for sensory and motor function of larynx (all muscles except the cricothyroid)
• hoarseness

800

In general describe the management of a "hot" vs "cold" thyroid nodule

• In patients with suppressed TSH, thyroid scintigraphy distinguishes a solitary toxic nodule ("hot nodule") from a toxic multinodular goiter (heterogeneous uptake) or Graves hyperthyroidism (diffuse, increased uptake).
• Hot nodules (increased uptake on scan) are almost always benign and do not warrant fine-needle aspiration (FNA) biopsy.
• Cold nodules warrant further workup with a thyroid ultrasound and FNA biopsy.

1000

DAILY DOUBLE

Describe the Bethesda criteria including all categories with the corresponding management

     

Hyperthyroidism

200

What are the 3 hormones produced by the Thyroid gland

• Hormones made within the thyroid gland include thyroxine (T4), triiodothyronine (T3), and calcitonin.

400

What is the most common cause of Hyperthyroidism

Graves disease

600

This is the most important factor regarding prognostication of well differentiated thyroid cancer

• Age is the most important factor regarding prognosis of well-differentiated thyroid cancer.
  • If the patient is younger than age 55, the cancer can only be stage 1 or stage 2.

800

Which is the preferred anti thyroid medication in pregnancy and why?

 PTU is the preferred medication in pregnancy.

safe during first trimester as it does not cross the placenta

1000

Why is a Euthyroid state preferred prior to undergoing total thyroidectomy for hyperthyroidism? (to prevent what?)

what are the signs/symptoms and management of this condition

To prevent thyroid storm

signs - CV dysfunctions, CNS manifestiations, hypertherima

management - cooling blankets, RAI, thyroidectomy

Hyperparathyroidism

200

Which branchial pouches the do superior and inferior parathyroid glands originate from

• 
  
  • The superior parathyroid glands are derived from the fourth branchial pouch. They are located posterolateral to the recurrent laryngeal nerve (RLN). 
  • The inferior parathyroid glands are derived from the third branchial pouch. They are located anteromedial to the RLN. 

400

What is the most common cause of Primary hyperparathyroidism 

solitary adenoma (80-90%)

600

What are the 3 ways PTH helps to increase serum calcium

PTH increases serum calcium by:

• Increasing bone resorption 
• Increasing renal calcium absorption in the ascending loop of Henle and distal convoluted tubule 
• Increasing conversion of 25-OH vitamin D to the active 1,25(OH)2D, which increases intestinal absorption of calcium 

800

What are 4 indications for asymptomatic patients to undergo parathyroidectomy 

• Age less than 50 years 
• Laboratory studies: serum calcium greater than 1 mg/dL above the upper limit of normal 
• Skeletal considerations
  • Bony fracture 
  • Osteoporosis as measured with a bone density T-score less than or equal to –2.5 on DEXA at any site 
• Renal considerations:
  • GFR less than 60 mL/min 
  • Nephrolithiasis or nephrocalcinosis 
  • Hypercalciuria (> 250 mg/d for females and > 300 mg/d for males)

1000

What would be the expected lab pattern of a patient with secondary hyperparathyroidism due to chronic renal insufficiency?

PTH, calcium, phosphate, vitamin D

elevated PTH levels, 

hypocalcemia, 

hyperphosphatemia, 

hypovitaminosis D.

Thyroid cancer

200

This is the most common thyroid cancer and spreads via what? (hematogenous vs lymph)

• Papillary thyroid cancer (PTC). This is the most common thyroid cancer composing 80% of cases. The prognosis is excellent when PTC is localized to the thyroid gland. PTC spreads via the lymph nodes. 
• Follicular thyroid cancer (FTC). This constitutes 10% of all thyroid cancers and is more prevalent in the setting of iodine deficiency. Spread is hematogenous. FTC has a slightly worse prognosis than PTC.

400

What are two buzzword histologic findings in Papillary thyroid cancer?

1.psammoma bodies (concentric lamellated calcified structures)

2. intranuclear inclusions and grooves, and papillae, with empty-appearing nuclei (“Orphan Annie eyes”)

600

How do you diagnose follicular thyroid cancer?

• FNA cannot be used to distinguish between benign and malignant follicular neoplasms because FTC is defined by capsular or vascular invasion (as compared with follicular adenomas, which are noninvasive).
• need diagnostic/therapeutic lobectomy

800

What is the surgical management of nonmetastatic medullary thyroid cancer?

What lab values are measured postoperatively as part of surveillance (two answers)

Nonmetastatic MTC should be treated with total thyroidectomy and bilateral central (level VI) neck dissection.

if nodes positive then MRND

CEA, calcitonin. Calcitonin more sensitive for recurrence

1000

How is thyroid lymphoma treated/managed?

• Thyroid lymphoma responds well to chemotherapy with rituximab, cyclophosphamide, doxorubicin (hydroxydoxorubicin), vincristine (Oncovin), prednisone (R-CHOP) and radiation.

Cancer continued

200

Following total thyroidectomy for well differentiated thyroid cancer, this can be used as a tumor marker for surveillance? 

In general when should this be initially checked post (timeframe)

Thyroglobulin

3-6 months post op

should also check a TSH

obtain U/S 6-12 mo postop

400

For which thyroid cancers is RAI indicated? 

 This therapy is indicated for patients with PTC or FTC after total thyroidectomy who have the following: 

• Large tumors (> 4.0 cm) 
• Distant metastases 
• Gross extrathyroidal extension or aggressive histologic features 
• Tumors from 1 to 4 cm with high-risk histology, vascular invasion, or cervical lymph node metastases

600

Patients with MTC should be screened for what gremlin genetic mutation?

• Genetic screening for germline RET mutation should be performed for all patients with MTC.

800

Patients presenting with serum calcium greater than 14mg/dl should raise concern for what pathology?

Parathyroid cancer

1000

What is the surgical resection goal in parathyroid cancer?

• 
  
  • The mainstay modality for parathyroid carcinoma is complete surgical resection. 
  • The planned surgical technique for parathyroid carcinoma is en bloc resection of the tumor and any contiguous structures to which it may be adherent, including the ipsilateral thyroid lobe or the recurrent laryngeal nerve, which should be sacrificed if clinically involved.
  • If preoperative findings indicate lymph node involvement, a therapeutic ipsilateral cervical compartment lymph node dissection is indicated. 
• Intraoperative
  • Intraoperative suspicion of carcinoma mandates complete en bloc resection of the tumor with grossly negative margins.